How close are we to developing a universal flu vaccine? Experts weigh in.
The numerous candidate vaccines target different unchanging parts of the flu virus. One potential target is hemagglutinin, a protein found on flu viruses. “This protein attaches to the surface of cells and initiates the infection in your body,” says Rafi Ahmed, PhD, director of Emory Vaccine Center at the Emory School of Medicine in Atlanta.
Hemagglutinin looks like mushrooms covering the outside of the flu virus, with its round head and stem. Ahmed says that the stalk is consistent across different flu strains. Some universal vaccine candidates aim to immunize against this stem.
Other universal vaccine contenders target multiple unchanging parts of the virus all in one shot. The idea is to prepare the immune system for any surprises that a new flu strain might bring. That’s the aim of the BiondVax shot, now in phase III clinical trials, the furthest along of the numerous candidates. It’s being tested in people to see how well it works.